import java.io.*;
import java.util.*;
import java.util.stream.*;

class Process {
    private int[] A;
    private int   v;

    Process(int[] A, int v) {
        this.A = A;
        this.v = v;
    }

    int getResult() {
        return (IntStream.of(A).sum() - v);
    }
}

public class Main {
    public static void main(String[] args) throws IOException {
        var bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        var printWriter    = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));

        // 入力
        int N = Integer.parseInt(bufferedReader.readLine().trim());

        int[] A = Stream.of(bufferedReader.readLine().trim().split("[ ]+")).mapToInt(Integer::parseInt).toArray();

        int v = Integer.parseInt(bufferedReader.readLine().trim());
        // 処理および出力
        printWriter.println((new Process(A, v)).getResult());
        
        bufferedReader.close();
        printWriter.close();
    }
}